This invention generally relates to improved multi-layer steel gaskets. More specifically the present invention relates to an improved anti-fret primer coating for a multilayer gasket.
Gaskets are used in a variety of locations in an internal combustion engines. The primary requirement of these gaskets is that they be able to maintain sealing capabilities at the operating temperatures of the engine for suitably long operational life. Known gaskets are typically made with rubber sealing layers applied to a metal layer in such a manner that the resultant gasket has alternating rubber and metal layers. One challenge faced by use of gaskets is wear.
Indeed, wear will often be the limiting factor in the operational life of a multilayer gasket. Typically, wear will eventually compromised the ability of the gasket to maintain a seal. The seal may be compromised by the break down of the metal layers caused by wear or abrasion of the metal layers against the engine parts. The vibrations/thermal expansion motions inherently present in an engine are the source of the abrasion. The abrasion eventually leads to cracking or fretting of the metal layers.
The seal may also be compromised by the delamination of the rubber sealing layers from the metal layers. Delamination results from the combination of poor adhesion between the metal and rubber layers and the motions of the engine. Forestalling fretting for as long as possible will increase the service life of the gasket. Currently, primers are only used to enhance adhesion and do not provide sufficient resistance to fretting.
The inventors have recognized a need for an improved primer that provides good adhesion with anti-fret benefits
The present invention relates to an improved primer coating for a multilayer gasket. The coating includes an elastomer, an epoxy resin and a particulate lubricant. The coating may also employ other components such as cure accelerators and reactive diluents. Also disclosed is a method of making the primer coating.